Spry vertical menu button shows background color instead of image in preview

Question

Hello All, I'm a newbie (to the forum and Dreamweaver) so my apologies if my question is not in good form.  I've searched for this issue but cannot seem to find the exact problem I have. 
I've created a website (my first) and used the spry menu bar.  It works well using the default blue and grey colors for button and hover.  However, I decided I want to spruce it up a little and change the buttons to use a background image (rainbow pattern) instead of background color.  I internet researched this for some time and watched all the youtube videos people have posted for this process and editing the spry vertical menu bar CSS.  Using the .a and hover lines from the CSS, I was able to add my background .jpg image file.  In the design view, the button look exactly how I want them to.  However, when I attempt to preview in IE, Chrome, or FF, the buttons still have the default colors and no image.  I've gone back and deleted the default blue and grey, but then the preview just shows dark grey and white for the buttoms.  is there something that I am overlooking that would cause the background color to show instead of the image I have attached to the buttons.  I can't figure out why it looks right in DW but not in preview.
BTW, I'm editing a template file and all the pages are updated with the new image buttons, but none of the pages show correctly in preview. 
Thanks

Answer 1

Point taken :-)
This is my spry vertical css code.  No sub-menus. 
DESIGN INFORMATION: describes color scheme, borders, fonts
/* Outermost menu container has borders on all sides */
ul.MenuBarVertical
border: 1px solid #CCC;
/* Submenu containers have borders on all sides */
ul.MenuBarVertical ul
border: 1px solid #CCC;
/* Menu items are a light gray block with padding and no text decoration */
ul.MenuBarVertical a
display: block;
cursor: pointer;
padding: 0.5em 0.75em;
color: #333;
text-decoration: none;
font-weight: bold;
background-image: url(/Images/Rainbow_Button.jpg);
background-color: ;
background-repeat: no-repeat;
background-position: center;
/* Menu items that have mouse over or focus have a blue background and white text */
ul.MenuBarVertical a:hover, ul.MenuBarVertical a:focus
background-color: #666666;
color: #333333;
background-image: url(/Images/Rainbow_Button_Hover.jpg);
/* Menu items that are open with submenus are set to MenuBarItemHover with a blue background and white text */
ul.MenuBarVertical a.MenuBarItemHover, ul.MenuBarVertical a.MenuBarItemSubmenuHover, ul.MenuBarVertical a.MenuBarSubmenuVisible
background-color: #0000FF;
color: #FFF;